Electromagnetic device for automated jacquard machine needle actuation

ABSTRACT

An electromagnetic device for controlling the needles of a Jacquard machine is provided. The electromagnetic device selectively actuates the needles of a Jacquard machine using solenoids. The solenoids control selector members and place them either in a deployed position or a withdrawn position. When the device is moved with respect to the needles of a Jacquard machine, those selector members that are in the deployed position engage pushers to move the associated needles.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject of the present invention is an electromagnetic device forthe automated actuation of the needles of a Jacquard machine, and aJacquard machine equipped with such a device. The invention relates morespecifically to a device intended to be moved with respect to theneedles of a Jacquard machine in order to push them selectively, in aselection that is established automatically on each cycle of theJacquard machine, under the control of electromagnetic means. Theinvention finds a particular, but not exclusive, application inreplacing the punched cards used in Jacquard machines for controllinglace-making machines, especially Leavers lace machines.

2. Description of the Related Art

It has already been proposed, particularly in European PatentApplication EP-A-0 382 998, that the conventional punched cards of aJacquard machine be replaced by an electromagnetic control device whichselectively pushes the needles of the Jacquard machine. This documentteaches the automatic control of the selection of each needle of theJacquard machine using a solenoid, and more particularly a two-positionsolenoid comprising two concentric windings known respectively as theattraction and release windings. Electric operation of the releasewinding allows a selector member, in the form of a rod, to be deployed,while electric operation of the attraction winding allows this selectorrod to be retracted. The device is also equipped with means allowing itto be moved with respect to the needles of the Jacquard machine. In afirst embodiment, illustrated in particular in FIG. 1 of this document,the selector rod of each solenoid is associated with a passage, and itsfunction is to close this passage when brought into the deployedposition. When the device comes into contact with the needles of theJacquard machine, all the needles which lie facing a respective passagewhich has been closed by a selector rod are pushed by the device when itmoves. By contrast, in the case of the passages which are not closed bya selector rod, the needles of the Jacquard machine lying opposite thesefree passages enter the said passages when the device moves, and aretherefore not pushed by this device. In a second embodiment illustratedin FIG. 4 of this document, the selector rods act respectively onintermediate pushers, and have the function of locking them in thedeployed position. When a pusher is locked in the deployed position, itallows the corresponding needle of the Jacquard machine to be pushedwhen the device is moved. When a pusher is not locked in the deployedposition, it is pushed back elastically by a return spring to aretracted position, and cannot come into contact with the associatedneedle.

The electromagnetic devices described in European Patent ApplicationEP-A-0 382 998 advantageously, on the one hand, allow those needles of aJacquard machine, which are to be pushed during a given cycle, to beselected automatically by an appropriate control of the electrical powersupply to the windings of each solenoid associated with a needle and, onthe other hand, allow the energy requirement for operating each solenoidto be very low. The solenoids described in this document do, however,have the drawback of being bulky and are therefore ill-suited toselecting needles in a Jacquard machine, which needles are arranged inconsecutive rows with a small inter-row spacing, particularly a spacingof less than 1 centimeter.

BRIEF SUMMARY OF THE INVENTION

The object of the present invention is to propose an electromagneticdevice which has the advantages of the devices of the aforementionedEuropean Patent Application, but which is made up of electromagneticselector members which require a smaller amount of space, so that it canbe adapted to the control of the needles in a Jacquard machine, theseneedles being arranged in closely-spaced consecutive rows. The device ofthe invention more specifically finds its application in Jacquardmachines used for controlling Leavers lace machines, and in which thespacing between two consecutive rows of needles is very small, and ofthe order of 6 mm. The invention is not, however, restricted to thisparticular type of Jacquard machine, but may be applied in general toany type of Jacquard machine controlled by needles which have to bepushed selectively and are arranged in consecutive rows. These may, inparticular, be Jacquard machines with cords or hooks for controllingtextile looms, and especially weaving looms. These may also be Jacquardmachines of the type described in French Patent Application FR-A-2 704562, in which the needles that are to be pushed, and known as fallingneedles, control the movement of flexible needles known as percussionneedles arranged to be transverse to the falling needles. Finally, theneedles of the Jacquard machine which are to be pushed selectively bythe device of the invention may be arranged vertically or horizontally.

In a way which is known from the devices described in European PatentApplication EP-A-0 382 998, the device of the invention, on the onehand, is intended to be moved in each cycle of the Jacquard machine withrespect to the needles so as to push them individually and selectivelyand, on the other hand, employs, for each needle, a selector memberwhich can move in a direction that is transverse to the direction ofpushing of the device between a first, selection, position and a second,withdrawn, position, and whose movement between the two, selection andwithdrawn, positions can be controlled electromagnetically in such a waythat as it moves, the device pushes only those needles of the Jacquardmachine which are associated with a selector member that is in theselection position.

In a way which is characteristic of the invention, the needles of theJacquard machine being arranged in parallel rows, the device comprises anumber of parallel plates spaced apart in pairs at a spacing which isthe same as the spacing separating two consecutive rows of needles; inthe space between two consecutive plates there are mounted, on the onehand, the selector members associated with the needles of the same row,which selector members can move in the same plane parallel to that ofthe plates and, on the other hand, there is, for each selector member, atwo-part electromagnetic circuit allowing the creation of at least oneinduced electromagnetic field which is oriented so that it is transverseto the plane of the plates, the two parts of the electromagnetic circuitbeing mounted, one on each of the opposing faces of these two plates andconsisting, respectively, of a wound main part with at least twoopposite electromagnetic polar ends, and an armature for closing theelectromagnetic field, this armature being positioned opposite the woundmain part; each selector member also comprises a magnetized part whichis positioned between the two parts of the associated electromagneticcircuit, so as to allow its movement to be controlled.

Within the context of the invention, it is conceivable for each plate tobe equipped on each of its two faces either exclusively with wound partsor exclusively with armatures for closing the electromagnetic field. Inthis case, a plate with wound parts is alternated with a plate withclosure armatures. In another alternative form of the plates of thedevice of the invention, all the plates will be of the same type, andeach plate comprises, on one of its faces, the wound parts of theelectromagnetic circuits and, on its other face, the closure armatureswhich are intended respectively to close each induced electromagneticfield of the wound parts of the adjacent plate. This alternative formhas the advantage of reducing the manufacturing costs, because all theplates are identical. In the context of this alternative form, the woundparts and the closure armatures of a plate may be separate, and forexample bonded one onto each face of each plate. However, as apreference, in order to simplify the manufacture of the plates, andthereby further reduce their cost of manufacture, each closure armatureof a plate preferably consists of the base of a ferromagnetic fieldframe, of which the part opposite the base is wound, and which is fixedthrough the plate in such a way that the base and the wound part of thefield frame lie one on each side of the plate.

As a preference, the device comprises, between each plate and for eachselector member, a separate pusher which can move with respect to theplates in the plane of the plates and in a direction that is transverseto the axis of movement of the selector members, and which can be lockedin the deployed position with respect to the plates by the associatedselector member, in which position the pusher can push the associatedneedle of the Jacquard machine when the device moves.

It is necessary for each pusher to be able to be placed in the deployedposition with respect to the plates and to the selector members by anyappropriate means so that, if need be, it can be locked in thisposition. This can be achieved in a first alternative form by moving theassembly formed by the parallel plates and the selector members withrespect to the pushers. In this first alternative form, the devicecomprises a reset plate, and the assembly formed by the parallel platesand the selector members can move in terms of translation with respectto the reset plate along the axis of the pushers, between a firstposition, in which all of the pushers are in contact with the resetplate, and in the deployed position, and a second position, in whichonly those pushers which are locked in the deployed position withrespect to the plates are brought into contact with the correspondingneedles of the Jacquard machine, the pushers which are not locked in thedeployed position not being driven and remaining in contact with thereset plate.

The motion applied to the assembly formed by the parallel plates and theselector members is limited in terms of frequency and/or amplitudebecause of the relatively high inertia of this assembly. In an attemptto alleviate this drawback, the device of the invention comprises, in asecond alternative form, a reset plate which can move in terms oftranslation with respect to the plates and to the selector members andalong the axis of the pushers, and the function of which, in each cycleof the Jacquard machine, is to bring the pushers into the deployedposition and hold them there with respect to the plates while theselector members are made to move.

The reset plate according to the invention may, in general, be used inany device which allows the needles of a Jacquard machine to be pushedautomatically and selectively via pushers that can be locked in thedeployed position by means of selector members. This additional featureof the invention is therefore independent of the use of the main meansof the invention, that is to say the particular structure in the form ofa number of parallel plates, with, for each inter-plate space, a numberof two-part electromagnetic circuits each allowing the creation of atleast one induced electromagnetic field oriented so that it istransverse to the plane of the plates, for controlling the movement ofeach member for selecting the needles of one same row. In particular,according to the invention, this reset plate could be fitted to thealternative version of FIG. 4 of European Patent Application EP-A-0 382998.

Other features and advantages of the invention will emerge more clearlyfrom reading the description which will now be given of a preferredembodiment of the invention, which description is given by way ofnonlimiting example, and with reference to the appended drawing, inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a part view from above of a device of the invention allowingautomatic selection of the falling needles of a Jacquard machine, theseneedles being arranged in parallel rows, there being eight needles perrow,

FIG. 2 is a view in section on a vertical plane of the device of FIG. 1between two consecutive plates,

and FIG. 3 is a view in section on a horizontal plane of the device ofFIG. 1, homing in on a selector member between two consecutive plates.

DETAILED DESCRIPTION OF THE INVENTION

The device of FIGS. 1 to 3 is intended to be mounted on a Jacquardmachine (not depicted) with falling needles 1, more commonly calleddroppers, like those used for operating a Leavers lace machine. Itreplaces the rotary cylinder which acts as a support and drives themistle thrush [sic] of punched cards traditionally used for selectivelypushing the needles of the Jacquard machine. In the particularembodiment which will now be described, the needles 1 of the Jacquardmachine are arranged in a number of consecutive rows spaced apart with aconstant spacing e, and each containing eight needles.

If reference is now made to FIGS. 1 and 2, the device comprises a numberof identical, parallel plates 2, which are spaced uniformly with aspacing e that is the same as that of the rows of needles in theJacquard machine, and which are secured to a perforated guide plate 3.In the particular embodiment illustrated, as the device is designed topush vertical falling needles 1 of a Jacquard machine, the plates 2 arevertical, while the perforated guide plate 3 is horizontal. Moregenerally, the perforated guide plate 3 will be oriented in a plane thatis transverse to the needles 1 of the Jacquard machine, and the plates 2will be oriented in a plane that is parallel to the plane of theneedles.

Each perforation 3a of the guide plate 3 is intended to face a needle 1of the Jacquard machine. If reference is made to FIG. 1, theseperforations are therefore arranged in a number of consecutive rows 4,there being eight perforations 3a per row, each row 4 of perforations 3acorresponding to a row of needles 1 of the Jacquard machine. Inaddition, the vertical plates 2 are arranged with respect to the guideplate 3 in such a way that one row 4 of perforations 3a lies between twoconsecutive plates 2. A limited number of rows 4 has been illustrated inFIG. 1. In practice, the Jacquard machine may have more than one hundredrows of needles.

Inserted between each plate 2 are eight vertical pushers 5, there beingone pusher 5 per needle 1 of a same row. The pushers 5 positionedbetween two plates 2 are each mounted so that they can slide in the sameplane 5a parallel to the plates 2, between a position that is retractedwith respect to the plates 2, hereafter known as the down position, anda position which is deployed with respect to the plates 2, hereafterknown as the up position, and are guided in their translation by twosupports 6a and 6b which allow each pusher 5 to be immobilizedhorizontally.

In FIG. 2, the device is positioned with respect to the needles of theJacquard machine in a so-called pushing position which is such that eachpusher 5 is vertically in line with a needle 1. In this pushingposition, the device can be given a movement of translation with respectto the needles 1 in a so-called pushing direction depicted by thedouble-headed arrow D and which, in this instance, is vertical. When thedevice is in its pushing position, only those pushers 5 which are in theup position come into contact with the corresponding needles 1 via theirupper end 5d known as the pushing end. Thus, in its pushing position,when the device moves vertically upwards, only those needles 1 that areassociated with a pusher 5 in the up position are raised by the devicewhen it moves. In the context of the invention, depending in particularon the specific type of Jacquard machine on which it is mounted, thedevice may either be constantly in its pushing position, and have asingle movement of translation with respect to the needles, or, on eachcycle of the Jacquard machine, in addition to the translational movementin the pushing direction, be given a movement which brings it into itspushing position.

Mounted in each space delimited by two consecutive plates 2 are eightselector members 7 which are positioned in the same plane 7a parallel tothe plates 2, that is to say, in this instance, in one same verticalplane. Each selector member 7 is associated with a pusher 5 and canslide horizontally under the action of electromagnetic means which willbe described later, between a selection position in which thecorresponding pusher 5 is locked in the up position, and a retractedposition in which the pusher 5 is no longer locked in the up positionand drops into the down position under the effect of gravity.

In the embodiment of FIG. 2, the eight selector members 7 aredistributed in two groups of four on each side of the pushers 5. Thefour selector members 7 of one same group are guided in their sliding bytwo supports 8a and 8b which allow each selector member 7 to beimmobilized vertically. Thus, when a pusher 5 is locked in the upposition by its selector member 7, and raises the corresponding needle 1of the Jacquard machine, the weight of this needle is taken up by thesupports 8a and 8b.

In the particular embodiment illustrated, each selector member consistsof a thin flat tab 9 of approximately rectangular shape. As is clear inFIG. 3, the plane 7a of the selector tabs 9 between two plates 2 isoffset with respect to the plane 5a of the pushers 5, so that thepushers 5 cannot obstruct the horizontal sliding of the selector tabs 9.The end 9a of each tab 9 terminates in a lateral lug 10 which isoriented so that it is transverse to the plane of the tab, so as tointersect the plane 5a of the pushers 5. Furthermore, a notch 5b, whichin this case is in the shape of a U, is made in each pusher 5. The notch5b of a given pusher 5 is designed in such a way that once the pusher 5is in the up position, it is at the same level as and in line with thetab 9. Thus, once a pusher 5 has been brought into the up position, whenthe corresponding tab 9 is brought into the selection position bysliding it horizontally, its lateral lug 10 becomes inserted in thenotch 5a of the corresponding pusher 5, and allows this pusher 5 to bevertically immobilized in the up position. By contrast, when the lug 10is disengaged from the notch 5b of the corresponding pusher 5, bysliding the tab 9 horizontally in the opposite direction, whichcorresponds to the position of the lug 10 shown in dotted line in FIG.3, the pusher 5 is no longer held vertically and drops into the downposition.

In a preferred alternative form, for the electromagnetic control of thesliding of the eight selector tabs 9 inserted between two plates 2, eachplate 2 is equipped with eight soft iron field frames 11 comprising abase 12 and three lateral legs forming an approximate E with the base12, namely two end legs 13a and a central leg 13b. A winding 14 is woundaround the central leg 13b. The two end legs 13a thus constitute twoelectromagnetic polar ends of the same sign, and the central leg 13bconstitutes a wound core forming an electromagnetic polar end of theopposite sign to the end poles 13a. The signs of the end poles 13a andof the central pole 13b will be fixed by the direction in which thecurrent flows through the winding 14.

Each field frame 11 is fixed through the plate 2 in an opening providedfor this, so that the base 12 is positioned on the face 2a of the plate2, and the poles 13a and 13b are positioned on the other face 2b of theplate 2. If reference is made to FIG. 3, it is clearly evident that thepoles 13a and 13b of a wound field frame 11 of a given plate 2 (thelower plate in FIG. 3) lie opposite the base 12 of the field frame 11 ofthe plate adjacent to it (upper plate in FIG. 3), and thus, with thisbase 12, form an electromagnetic circuit allowing two opposed inducedelectromagnetic fields C1 and C2 to be created locally in the spacebetween plates 2. These two electromagnetic fields are oriented so thatthey are transverse to the plane of the plates 2 and have been depicteddiagrammatically by two dotted lines in FIG. 3. In other words, the base12 of the wound field frames 11 of each plate 2 constitutes an armaturewhich closes the two electromagnetic fields induced by the wound partopposite of the adjacent plate, which wound part is formed of two endpoles 13a and of a central pole 13b.

Each selector tab 9 is equipped with two permanent magnets 15a and 15bmounted in opposition. Each pair of magnets 15a and 15b of a selectortab 9 is positioned between the base 12 and the three poles 13a, 13b ofa given electromagnetic circuit. In FIG. 2, for reasons of clarity, onlythe windings 14 of each electromagnetic circuit have been depicted indotted line, the field frames 11 of the plates 2 not having beendepicted. As is clearly apparent from this figure, the electromagneticcircuits are split into two groups of four circuits, on each side of thepushers 5, and the circuits of one same group are laterally offset inthe plane of the plate, which makes it possible to obtain a saving interms of height. Obviously, this same offset is to be found with thepairs of magnets 15a and 15b of the tabs 9 of one same group.

The two magnets 15a and 15b of a tab 9 constitute a dipole, thedimensions of which are such that it can route its magnetic field ontoone or other of the end poles 13a, depending on the direction of the twoinduced electromagnetic fields C1 and C2, that is to say depending onthe direction in which current is made to flow through the winding 14.In FIG. 3, the dipole which consists of the two magnets 15a and 15b ofthe tab 9 tends to route its magnetic field onto the right-hand end pole13a of the wound field frame 11 of the lower plate 2, the tab 9 thusexperiencing a force which tends to move it to the right. A firstindexing stop 16 is provided, at the end 9a of the tab 9 and allows thetab to be kept stably in this position, which corresponds to itsselection position, the lug 10 being inserted in the notch 5b of thepusher 5. When the direction of the flow of current through the winding14 is reversed, the direction of the two induced electromagnetic fieldsC1 and C2 reverses. The dipole formed by the two magnets 15a and 15btries to route its magnetic field onto the left-hand end pole 13a, whichcauses the selector tab 9 to move to the left. At the ends 9b of eachtab 9 there is a second indexing stop 17 (FIG. 2). The tab 9 istherefore brought into a stable position against this stop 17 (theposition in dotted lines in FIG. 3), which position corresponds to thewithdrawn position of the selector tab, the lug 10 being disengaged fromthe notch 5b in the pusher 5. The function of the two indexing stops 16and 17 is to prevent the dipole formed by the two magnets 15a and 15bfrom moving forward as far as a position in which it would be centeredon the corresponding end pole 13a.

The particular alternative embodiment illustrated in FIG. 3, andemploying three electromagnetic polar ends 13a, 13b, a pair of magnets15a, 15b mounted in opposition, and two indexing stops 16 and 17,advantageously makes it possible to obtain a selector member 7 whichremains stable in its withdrawn position or in its selection position,even if the current in the winding 14 is cut off. Indeed, when thecurrent in the winding 14 is cut off once the selector member 7 is inits withdrawn or selection position, the dipole formed by the twomagnets 15a and 15b, on account of its magnetic field, attempts tocenter itself on the corresponding polar end 13a, that is to say, inFIG. 3, on the right-hand polar end 13a when the selector member 7 is inthe selection position, and on the left-hand polar end 13a when theselector member is in the withdrawn position. The selector membertherefore remains continuously pressed against the correspondingindexing stop 16 or 17, even when there is no current flowing throughthe winding 14. By virtue of this alternative form, on the one hand, itis unnecessary, once the selector member has been brought into itsretracted or selection position, for current to be maintained in thewinding 14 for all of the time during which the needles of the Jacquardmachine are being pushed and, on the other hand, the control of theJacquard machine is not affected in the event of an instantaneous breakin current in a winding during a cycle.

Referring to FIG. 2, in order to supply electrical power to the windings14 of the field frames 11, each plate 2 is fitted with a connector 18with nine terminals 19, and acts as a support for a printed circuit 20allowing one of the two ends of each winding 14 to be connected to onesame terminal 19 which acts as a common ground, and the other end ofeach winding 14 to a given terminal 19. The terminals 19 of theconnector 18 of each plate 2 are connected to a processing unit (notdepicted) which is programmed to deliver, on each cycle of the Jacquardmachine, the operating voltage required for each winding 14, dependingon whether or not the corresponding tab 9 is to lock the correspondingpusher 5 in the up position, this amounting to a simulation of a solidpart or of a hole, respectively, in a punched card.

For it to be possible for the pushers 5 to be locked in the up position,it is necessary for them to be brought mechanically into this positionprior to locking them. This is achieved using a reset plate 21 which canmove in terms of translation with respect to the plates 2 and to theselector tabs 9, and along the axis 5e of the pushers 5, between a downposition and an up position which are depicted in dotted line in FIG. 2.In the example illustrated, all the pushers 5 consist of rods of thesame length, whose lower end 5c, known as the setting end, projects withrespect to the lower edge of the row of plates 2, at least when thepusher 5 is in the down position. The reset plate 21 is positioned insuch a way that when it is in the down position, the reset ends 5c ofthe pushers 5 which are in the down position come into contact with theupper face of the plate 21.

The way in which the device just described with reference to FIGS. 1 to3 operates is as follows. On each cycle of the Jacquard machine, thedevice is in a so-called reset position, in which none of the pushers 5,irrespective of its position, can come into contact with the needles 1.When the device is in this reset position, the reset plate 21 is broughtinto the up position, and pushes into the up position all those pusherswhich were not locked in the up position in the previous cycle. Next,while the reset plate is in the up position, the processing unit (notdepicted) delivers the appropriate voltages for each winding 14, so asto bring or, as appropriate, keep the corresponding selector tab 9 intoor in the withdrawn or selection position. Next, the reset plate 21 islowered. The pushers 5, the selector tab 9 of which is in the withdrawnposition, drop under gravity into the down position. The other pushersare locked in the up position with respect to the plates 2. Next, theentire device is, as appropriate, brought into the pushing position aswas described earlier, and is then moved into the pushing direction D inorder to individually raise those needles of the Jacquard machine whichhave been selected.

The reset plate 21 advantageously has low inertia and therefore allowsmovements of a high frequency with a relatively large amplitude. Theoutward and return movement of the reset plate 21 between its downposition and its up position corresponding to the incremental rotationof the drive cylinder conventionally used for driving the punched cards.Advantageously, use will be made of means which already exist in theJacquard machine for rotating the cylinder which has been replaced bythe device of the invention, for raising and lowering the reset plate21.

The main advantage of the invention lies in the fact that it makes itpossible to produce a device in which the spacing e between twoconsecutive plates can be very small, and is furthermore independent ofthe number of needles per row in the Jacquard machine. In particular, ithas been possible to produce a device according to FIGS. 1 to 3 thatallows the control of the needles 1 of a Jacquard machine in which theconsecutive rows were spaced at a spacing e of 6 mm.

Another advantage of the invention lies in its modular design. It isactually very easy to modify a given design to adapt it to anotherJacquard machine with the same spacing e between rows, but which mayhave a different number of rows of needles, or alternatively a differentnumber of needles per row. All that is required for this is for thedesired number of plates 2, of selector members 7 and of pushers 5 to beremoved or added. It should, at this point, be pointed out that as theselector members 7 and the pushers 5 are simply mounted so that they canslide with respect to the plates 2, they are very easy to assemble or,on the other hand, disassemble in the inter-plate spaces, and theseoperations require no special tools.

The invention is not restricted to the preferred embodiment describedwith reference to FIGS. 1 to 3. By way of non-exhaustive examples, thedevice of the invention may be produced in the following versions:

It is conceivable for use to be made of two-pole wound field frames forthe electromagnetic control of the selector members. In this case, eachelectromagnetic circuit creates just one induced electromagnetic fieldand each selection member will comprise just one permanent magnet. Inthis alternative version, when a winding is powered with a givenvoltage, it causes the selector member to move in order to bring it tothe end of its travel in a given position. This may either be thewithdrawn position or the selection position. Each selector memberfurther comprises an elastic return means, for example a coil spring,which is compressed when the selector member is kept in theend-of-travel position by the electromagnetic means. When the current inthe winding 14 is cut off, the elastic return means returns the selectormember in the opposite direction into its withdrawn or selectionposition, as the case may be.

In another alternative form, the axis 5e of the pushers 5 may behorizontal. In this alternative form, the pushers can no longer dropback into the retracted position under gravity. In this version, eachpusher will therefore be fitted with an elastic return means of the coilspring type which is compressed when the pusher is in its deployedposition and whose function is to return the pusher to the retractedposition by relaxing, when the pusher is no longer selected and when thereset plate leaves its position in which it keeps the pushers in thedeployed position.

The use of pushers advantageously allows the production of selectormembers which have a very short travel, and more particularly a travelwhich is smaller than the width 1 of a needle (FIG. 2). It is thereforepossible to control the needles of a Jacquard machine in which thedistance d between two adjacent needles of one same row (FIG. 2) is lessthan the width 1 of a needle. It has thus been possible to produce apushers device according to FIGS. 1 to 3 with an inter-pusher distance,which corresponds to the distance d, of about 2 mm. However, in thecontext of the invention, if the distance d is not a restricting factor,and in particular is equal to or exceeds the width 1, it is conceivablefor the needles to be operated directly by the selector members. In thiscase, each selector member will be designed to close the correspondingorifice 3a in the guide plate 3. The selector members will, for example,consist of flat L-shaped tabs.

In the context of the alternative form of FIGS. 1 to 3, the reset plate21 pushes each pusher 5 via its setting end 5c which is the opposite endto its pushing end 5d, and which projects with respect to the plates 2.The reset plate may therefore advantageously consist of a simple, thin,solid plate. In another alternative form, the reset plate may be aperforated plate through which the pushing ends 5d of the pushers 5 passand whose function is to pull the pushers into the deployed position.For this purpose, each pusher will be equipped, for example, with acollar at its pushing end. The function of this collar will be tointeract with the reset plate in order to bring the pusher into thedeployed position. In this alternative form, it is unnecessary for thesetting end 5c of the pushers 5 to project with respect to the plates,and each selector member 7 may be designed in such a way as toimmobilize the corresponding pusher 5 in the deployed position at itsreset end, in a similar way to the alternative form of FIG. 4 ofEuropean Patent Application EP.A.0.382.998.

Finally, in another embodiment of the invention, the pushers 5 areplaced in the deployed position with respect to the plates 2, not bytranslation of the reset plate 21 in the direction of the pushers, butrather by a translation with respect to the reset plate 21 of theassembly formed by the plates 2 and the selector member 7, along theaxis 5e of the pushers 5. The way in which this embodiment works is asfollows. Prior to moving the selector members 7, the plates 2--selectormembers 7 assembly is brought toward the reset plate 21, into a firstposition in which all the pushers 5 are in contact with the reset plate.During this movement, the pushers 5 which are locked in the deployedposition with respect to the plates 2 are driven toward the reset plate21, while the other pushers 5 which are not locked in the deployedposition remain unmoved in contact with the reset plate 21. In thisfirst position of the plates 2--selector members 7 assembly, all thepushers 5 are placed in the deployed position with respect to the plates2. Once the plates 2--selector members 7 assembly has been brought intothis first position, the appropriate selector members 7 are made to moveso as to lock selectively in the deployed position those pushers 5 whichare to act on the needles of the Jacquard machine 5 during the nextcycle. Once the appropriate pushers 5 have been locked in the deployedposition, the plates 2--selector members 7 assembly is moved in theopposite direction with respect to the reset plate. The pushers 5 whichare locked in the deployed position are driven by this assembly as faras the second position in which the pushers 5 which are locked in thedeployed position come into contact with the corresponding needles ofthe Jacquard machine. Those pushers 5 which are not locked with respectto the plates 2 remain unmoved, in contact with the reset plate 21, the(plates 2--selector members 7--pushers 5 locked in the deployedposition) assembly sliding with respect to the unlocked pushers 5.

What is claimed is:
 1. A Jacquard machine having a device for automatedactuation of needles of the Jacquard machine, the needles being arrangedin parallel consecutive rows having a spacing between the rows, thedevice, being adapted to be moved in each cycle of the Jacquard machinewith respect to the needles to push the needles individually andselectively and employing, for each needle, at least one of a pluralityof selector members which are adapted to move in a direction that istransverse to a direction of pushing of the device between a first,selection, position and a second, withdrawn, position, and whereinmovement between the two, selection and withdrawn, positions can becontrolled electromagnetically in such a way that as the device moves,the device pushes only those needles of the Jacquard machine which areassociated with a selector member that is in the selection position,wherein the device comprises a number of parallel plates spaced apart inpairs at a spacing which is adapted to be the same as the spacingseparating two consecutive rows of needles, and wherein the selectormembers associated with the needles of the same row are mounted in thespace between two consecutive plates, the selector members being adaptedto move in a plane parallel to a plane of the plates, wherein for eachselector member, there is a two-part electromagnetic circuit allowingthe creation of at least one induced electromagnetic field which isoriented so that it is transverse to the plane of the plates, the twoparts of the electromagnetic circuit being mounted, one on each opposingface of two plates and comprising, respectively, a wound main part withat least two opposite electromagnetic polar ends, and an armature forclosing the electromagnetic field, the armature being positionedopposite the wound main part, each selector member comprising amagnetized part which is positioned between the two parts of theassociated electromagnetic circuit, so as to allow movement of theselector member to be controlled.
 2. The Jacquard machine according toclaim 1, wherein each plate of the device comprises, on one of itsfaces, the wound part of the electromagnetic circuit and, on its otherface, the armature which is intended to close the inducedelectromagnetic field of the wound part of the adjacent plate.
 3. TheJacquard machine according to claim 2, wherein each armature of a plateof the device consists of a base of a ferromagnetic field frame, ofwhich the part opposite the base is wound, and which is fixed throughthe plate in such a way that the base and the wound part of the fieldframe lie one on each side of the plate.
 4. The Jacquard machineaccording to one of claims 1 to 3, wherein each wound part of the devicecomprises three electromagnetic polar ends, respectively forming two endelectromagnetic poles of the same sign, and a central electromagneticpole of the opposite sign, which constitutes the wound core, wherein themagnetized part of each selector member consists of two permanentmagnets mounted in opposition in such a way that by controlling thedirection which current flows through the winding of the central pole,the movement of the selector member in one direction or in the otheralong an axis of movement is controlled, so as to bring it to the end ofits travel in the selection position or in the withdrawn position. 5.The Jacquard machine according to claim 2, wherein each plate of thedevice is fitted with a connector for supplying power to the windings,and acts as a support for a printed circuit connecting each winding tothe connector.
 6. Jacquard machine according to claim 1, wherein thedevice further comprises, between each plate and for each selectormember, a separate pusher which can move with respect to the plates inthe plane of the plates and along an axis in a direction that istransverse to the axis of movement of the selector members, and whichcan be locked in a deployed position with respect to the plates by theassociated selector member, in which position the pusher can push theassociated needle of the Jacquard machine when the device moves.
 7. TheJacquard machine according to claim 6, wherein the device furthercomprises a reset plate, and wherein an assembly formed by the platesand the selector members can move in terms of translation with respectto the reset plate along the axis of the pushers, between a firstposition, in which all of the pushers are in contact with the resetplate, and in the deployed position, and a second position, in whichonly those pushers which are locked in the deployed position withrespect to the plates are brought into contact with the correspondingneedles of the Jacquard machine, the pushers which are not locked in thedeployed position not being driven and remaining in contact with thereset plate.
 8. The Jacquard machine according to claim 6, wherein thedevice further comprises a reset plate which can move in terms oftranslation with respect to the plates and to the selector members andalong the axis of the pushers, and the function of which, in each cycleof the Jacquard machine, is to bring the pushers into the deployedposition and hold them there with respect to the plates while theselector members are made to move.
 9. The Jacquard machine according theclaim 8, wherein the axis of the pushers of the device is vertical, andthe reset plate can move between a down position and an up position inwhich it supports all the pushers in the deployed position, so that thepushers which are not locked in the deployed position by their selectormember drop back into a retracted position under gravity when the resetplate moves from its up position to its down position.
 10. The Jacquardmachine according to claim 8, wherein the axis of the pushers of thedevice is horizontal and in that each pusher comprises an elasticposition-return means which is compressed when each pusher is kept inthe deployed position by the reset plate, and which allows the pusher tobe returned to the retracted position when the reset plate leaves itsposition.
 11. The Jacquard machine according to claim 7, wherein thepushers of the device further comprise rods of identical length, with afirst, pushing, end intended to come into contact with a needle, and asecond, setting, end which projects from the row of plates and isintended to come into contact with the reset plate.
 12. The Jacquardmachine according to claim 11, wherein the selector members of thedevice consist of flat tabs, wherein in the space between twoconsecutive plates, all the pushers are positioned in a same planeparallel to the plates, and all the tabs are positioned in a same planeparallel to the plates but offset with respect to the plane of thepushers, so that the pushers do not obstruct the movement of the tabs,in that each pusher comprises a notch for immobilizing it in thedeployed position, and in that each tab comprises a lateral lug which istransverse to the plane of the tab and which, when the tab is broughtinto the selection position, becomes inserted in the notch in thecorresponding pusher in order to lock it in the deployed position. 13.In combination:a Jacquard machine having needles arranged in parallelconsecutive rows, each row having a spacing therebetween; and a devicefor automated actuation of the needles of the Jacquard machine, thedevice being adapted to be moved with each cycle of the Jacquard machinewith respect to the needles to push the needles individually andselectively, the device comprising:a number of parallel plates spacedapart in pairs at a spacing adapted to be the same as the spacingseparating two consecutive rows of needles in the Jacquard machine; aplurality of selector members mounted in the spacing between two platesof a pair and associated with a corresponding row of needles, theselector members being adapted to move in a same plane parallel to aplane of the plates and in a direction that is transverse to a directionof pushing of the device; and a two-part electromagnetic circuit foreach selector member allowing the creation of at least one inducedelectromagnetic field, the electromagnetic circuit being orientedtransverse to the plane of the plates, two parts of the electromagneticcircuit being mounted on opposing faces of two plates and including awound main part with at least two opposite electromagnetic polar ends,and an armature for closing the electromagnetic field, the armaturebeing positioned opposite the wound main part, wherein each selectormember comprises a magnetized part positioned between the two parts ofthe associated electromagnetic circuit to allow the movement of themagnetized part to be controlled.